That will take some doing after 12,200 people packed the MGM Grand Garden Arena on Friday afternoon to watch Floyd Mayweather and Saul Canelo Alvarez step on the scales to make their Saturday night meeting for the WBC super welterweight title official.

With the partisan Canelo fans cheering for their Mexican hero and the Money Team backing Mayweather, the atmosphere was far more electric than any weigh-in in recent boxing history. Now it’s up to the 36-year-old Mayweather (44-0, 26 KOs) and the 23-year-old Alvarez (42-0-1, 30 KOs) to put on a performance worthy of the record-breaking numbers the pay-per-view event is expected to generate.

Shane Mosley is confident it will. The former lightweight, welterweight and junior middleweight champion has been in the ring against both fighters, losing by decision to Mayweather in May 2010 and also by decision to Alvarez in May 2012.

“It’s going to be a great fight,” Mosley said. “Floyd is very smart in the ring. But Canelo is smart in the ring and has good defense. Canelo has to jump on Floyd and use his power to out-will Mayweather. It’s going to be up to the fighters to see who wants to win the most.”

To the relief of many, Alvarez made weight, landing precisely on the 152-pound catch weight for the 154-pound belt. Mayweather weighed 150 ¹/₂ pounds. There had been rumors Alvarez was struggling in recent days to take off the weight. But he insisted he made weight on Thursday.

“It was not a problem,” he said through an interpreter.

When asked if he was ready to fight, Alvarez didn’t need anyone to translate for him.

“I was born ready,” he said in perfect English.

Mayweather was born for events like this. The MGM Grand Garden Arena normally closes off half the building for weigh-ins, for which 5,000 is a huge attendance. The decision to the use the full seating, except for a few thousand behind the jumbo screen and stage, added to the big-event feel. Several thousands were turned away after the arena reached capacity about an hour before the weigh-in actually began.

Give Mayweather credit for becoming big box office. He’ll earn $41 million, while Alvarez will pocket around $12 million. “The turnout was amazing,” Mayweather said. “It’s the biggest weigh-in in the history of the sport. I’m ready to fight.”

Mayweather somehow wound up with Alvarez’s championship belt and tried to hand it to the defending champion. Alvarez refused to accept Mayweather’s offering.

“You know how those young kids are,” Mayweather said. “I’ve just got to go out and teach the kid a few things.”

Alvarez’s youth and strength are his biggest assets tonight. A perfectly placed punch on the chin or to the liver could put Mayweather in trouble. But if that doesn’t happen in the first few rounds, it will be Mayweather’s fight. Alvarez, who fades in the late rounds, hasn’t fought anyone close to Mayweather’s caliber and will have to stay poised to have a chance. He’ll also have to be steady and accurate with his jab. His hand speed could be faster than Mayweather anticipates.

“Every man has a shot to win,” said Peter “Kid Chocolate” Quillin, the WBO middleweight champion from New York. “But Floyd has been undefeated for 17 years. People are still looking for the lucky punch or finding a blueprint on how to beat him. Nobody has done that. But if Canelo is going to show anything great, he’s got to show it right now. Floyd Mayweather thrives on this kind of energy. He looks ready.”

“Floyd Mayweather has experience, but Canelo is young and strong,” he said. “It just depends on which Mayweather shows up and which Canelo shows up. I’ve seen both at their best. If both are at their best, I’ll go with Mayweather.”

Mayweather remained confident.

“I’ve been here before,” he said. “I know what it takes: hard work and dedication and belief in a good team. We’re 44-0. Saturday, 45-0.”

PREDICTION: Canelo could have his moments early, but Mayweather is too savvy and too skilled. He’ll find a way to survive and win on points.